1. Field of the Invention
The present invention relates to an arrangement for moving a printing head, for example of the non-impact type, by means of a direct-current electric motor.
In printing devices in which the impression of the character to be printed takes place without impact of the character-bearing element against the recording medium, the use of direct-current electric motors is very convenient, above all where the printing head is very light. In this case, a motor of limited power is sufficient for producing the translation of the head.
2. Description of the Prior Art
An arrangement is known in which a direct-current electric motor rotates a transmission belt extending along the entire printing line. In this arrangement, two hooks carried by the belt engage alternately with a pin on the head to translate it at constant speed during the printing stage. Having arrived at the end of the printing line, the hook disengages itself from the pin and the head returns rapidly to the starting position, restored by a spring which is loaded during the printing stage.
This arrangement, however, has the disadvantage that the return of the head takes place abruptly and that suitable and complicated means must be provided for checking the head when it reaches the starting position. Moreover, even when the head has to print a few characters in a line, it must travel the length of the whole of the printing line before being able to return, with a consequent waste of time.